Mirror display and method of manufacturing the same

ABSTRACT

A mirror display includes a light source, a light guide plate configured to guide light emitted from the light source, a first electrode layer spaced apart from the light guide plate and including at least one first hole, a first spacer provided between the light guide plate and the first electrode layer, a second electrode layer spaced apart from the first electrode layer and including at least one second hole not facing the first hole, and a substrate provided on the second electrode layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2015-0134817, filed on Sep. 23, 2015, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

1. Field

The exemplary embodiments relate to a mirror display and a method ofmanufacturing the mirror display.

2. Description of the Related Art

Light incident on mirrors may be delivered to users because mirrorsreflect light. The reflectivity of mirrors is an optical property.Mirrors having high reflectivity may reflect a large portion of incidentlight toward users. However, mirrors having low reflectivity may reflecta relatively small portion of incident light toward users.

Displays have many pixels, and each pixel outputs light having aparticular wavelength and a particular degree of intensity so thatviewers may recognize images displayed on the displays.

Such mirrors and displays may be combined as mirror displays. Mirrordisplays may function as mirrors when displays are not operated. Inaddition, displays and mirrors of mirror displays may be used at thesame time. An exemplary mirror display may be provided by combining aliquid crystal display with a transflective film. The transflective filmmay transmit images displayed on the liquid crystal display so thatviewers may view the images, and may function as a mirror by reflectinga portion of incident light. However, the transflective film maydecrease the light transmission efficiency of the liquid crystaldisplay. Moreover, there may be a limit to increasing the reflectivityof the transflective film because of a trade-off relationship betweenreflection of incident light and transmission of images formed by theliquid crystal display.

SUMMARY

Exemplary embodiments may provide a mirror display includingmicro-optical switches.

Exemplary embodiments may provide a method of manufacturing a mirrordisplay through simple processes.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented exemplary embodiments.

According to an aspect of an exemplary embodiment, a mirror displayincludes: a light source; a light guide plate configured to guide lightemitted from the light source; a first electrode layer spaced apart fromthe light guide plate and including at least one first hole; a firstspacer provided between the light guide plate and the first electrodelayer; a second electrode layer spaced apart from the first electrodelayer and including at least one second hole not facing the first hole;and a substrate provided on the second electrode layer.

in response to applying a voltage between the first electrode layer andthe second electrode layer, the first electrode layer may be movedtoward the second electrode layer.

In response to applying a voltage between the first electrode layer andthe second electrode layer, the second electrode layer may not be moved.

In response to applying a voltage between the first electrode layer andthe second electrode layer, the first electrode layer may close thesecond hole.

The substrate may include a transparent material.

The substrate may include a glass substrate.

The mirror display may further include an insulation layer provided onthe second electrode layer.

The mirror display may further include an optical film covering the atleast one second hole.

The optical film may include a diffusing plate or a polarizing plate toguide light in a predetermined direction.

The light source may include a plurality of light sources configured toemit light having different wavelengths.

The plurality of light sources may be turned on and off in a timesequence so as to display color images.

The mirror display may further include an image signal inputterconfigured to control light transmission by varying a time period duringwhich a voltage is applied between the first electrode layer and thesecond electrode layer.

The substrate may be provided on a side of the second electrode layerthrough which light passing through the second hole is output.

The second electrode layer may have a reflectivity of 70% or greater.

The second electrode layer may reflect external light incident on themirror display.

The mirror display may further include a gap formed between the lightguide plate and the first electrode layer.

The mirror display may further include a second spacer provided betweenthe first electrode layer and the second electrode layer.

The first electrode layer may include pixel electrodes, and the secondelectrode layer may include a common electrode.

According to an aspect of another exemplary embodiment, a method ofmanufacturing a mirror display includes: preparing a light guide plate;providing a first electrode layer on a substrate; etching the firstelectrode layer to form at least one first hole in the first electrodelayer; providing a second electrode layer spaced apart from the firstelectrode layer; etching the second electrode layer to form at least onesecond hole in the second electrode layer; providing the secondelectrode layer to face the light guide plate; and coupling the secondelectrode layer to the light guide plate using a first spacer.

The method may further include: providing a first layer on the firstelectrode layer; etching the first layer to form a hole; forming asecond spacer by filling the hole with a spacer material; providing thesecond electrode layer on the first layer; and removing the first layer.

The etching the second electrode layer may include etching the secondelectrode layer such that the second hole does not face the first hole.

The first electrode layer may have a reflectivity of 70% or greater.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the exemplary embodiments,taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view illustrating a mirror display according to anexemplary embodiment;

FIG. 2 is a partial cross-sectional view illustrating the mirror displayaccording to an exemplary embodiment;

FIG. 3 is a cut-way view illustrating a micro-optical switch of themirror display according to an exemplary embodiment;

FIG. 4 is a view illustrating a turned-on micro-optical switch of themirror display according to an exemplary embodiment;

FIG. 5 is a view illustrating turning on and off of a micro-opticalswitch array of the mirror display according to an exemplary embodiment;

FIG. 6 illustrates an exemplary case in which the mirror displaydepicted in FIG. 2 further includes a light reflecting layer 25 and anoptical film 47 according to an exemplary embodiment;

FIG. 7 illustrates an exemplary case in which the mirror displaydepicted in FIG. 2 further includes an anti-adhesion layer according toan exemplary embodiment;

FIG. 8 is a view illustrating an exemplary usage of the mirror displayaccording to an exemplary embodiment; and

FIGS. 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19 are viewsillustrating a method of manufacturing a mirror display according to anexemplary embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. In this regard,the present exemplary embodiments may have different forms and shouldnot be construed as being limited to the descriptions set forth herein.Accordingly, the exemplary embodiments are merely described below, byreferring to the figures, to explain aspects. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

A mirror display and a method of manufacturing the mirror display willnow be described with reference to the accompanying drawings accordingto exemplary embodiments.

In the drawings, like reference numbers refer to like elements, and thesize of each element may be exaggerated for clarity of illustration. Itwill be understood that although the terms “first”, “second”, etc., maybe used herein to describe various components, these components shouldnot be limited by these terms. These terms are only used to distinguishone element from another.

As used herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including” as used herein specify thepresence of stated features or elements, but do not preclude thepresence or addition of one or more other features or elements.

In the description of the exemplary embodiments, terms such as units ormodules are used to denote a unit having at least one function orperforming at least one operation and implemented with hardware,software, or a combination of hardware and software. In addition,expressions such as “A is provided on B” may be construed that A isprovided on B in a contact or non-contact manner.

FIG. 1 is a schematic view illustrating a mirror display according to anexemplary embodiment.

The mirror display may include a light source 10, a light guide plate 20configured to guide light emitted from the light source 10, and amicro-optical switch array SA configured to transmit or block lightincident from the light guide plate 20.

For example, the light source 10 may include a cold cathode fluorescentlamp (CCFL), a light emitting diode (LED), an organic light emittingdiode (OLED), or a laser diode (LD). The light guide plate 20 transmitsand reflects light emitted from the light source 10 such that the lightmay be uniformly transmitted from one side to the other side of thelight guide plate 20.

For example, the light guide plate 20 may include a transparent materialsuch as glass or a transparent plastic. The light guide plate 20 may beflat. However, the light guide plate 20 is not limited thereto. Forexample, the light guide plate 20 may have a wedge shape for improvinglight guiding efficiency and uniformity. The light source 10 may bedisposed on one or more lateral sides of the light guide plate 20.

The micro-optical switch array SA may include a plurality ofmicro-optical switches MOS. For example, the micro-optical switches MOSmay be arranged in a 2D matrix form. The micro-optical switches MOS maybe independently turned on and off. The micro-optical switches MOS maybe independently turned on and off by an electrical or mechanicalmethod. For example, each of the micro-optical switches MOS may form apixel PX of the mirror display. The amount of light transmission may beadjusted by controlling on and off times of the micro-optical switchesMOS forming the pixels PX of the mirror display. That is, themicro-optical switch array SA may transmit light emitted from the lightsource 10 while individually adjusting the amount of light transmissionthrough the pixels PX. If the light source 10 emits light having aplurality of wavelength bands, color images may be displayed on themirror display. This will be further described later.

FIG. 2 is a cross-sectional view illustrating one of the pixels PX ofthe mirror display depicted in FIG. 1, and FIG. 3 is a partial cut-awayview illustrating one of the micro-optical switches MOS.

For example, the light source 10 may include a first light source 11, asecond light source 12, and a third light source 13. The first lightsource 11, the second light source 12, and the third light source 13 mayemit light having different wavelengths, respectively. For example, thefirst light source 11 may emit red light, the second light source 12 mayemit green light, and the third light source 13 may emit blue light. Forexample, a plurality of first light sources 11, a plurality of secondlight sources 12, and a plurality of third light sources 13 may beprovided. In this case, for example, the first light sources 11, thesecond light sources 12, and the third light sources 13 may bealternately arranged in rows on a lateral side of the light guide plate20. FIG. 2 illustrates an example in which the first to third lightsources 11 to 13 are arranged in a thickness direction of the lightguide plate 20. However, the first to third light sources 11 to 13 arenot limited thereto. In another example, the first to third lightsources 11 to 13 may be arranged on a lateral side of the light guideplate 20 in a length direction of the light guide plate 20. The numbersand arrangement of the first to third light sources 11 to 13 may bevaried by taking into account the brightness and optical efficiency ofthe light source 10. For example, since green light sources have opticalefficiency lower than the optical efficiency of other light sources,more green light sources may be arranged. For example, light sources 10may be disposed on opposing sides of the light guide plate 20.

The micro-optical switches MOS may be provided on an exit surface 20 aof the light guide plate 20. Herein, the term “exit surface” refers to asurface through which light exits. The micro-optical switches MOS may beseparate from the exit surface 20 a of the light guide plate 20. To thisend, a first spacer 33 may be provided between the light guide plate 20and the micro-optical switches MOS. The micro-optical switches MOS mayinclude: a first electrode layer 30 separate from the light guide plate20; and a second electrode layer 40 separate (e.g., spaced apart) fromthe first electrode layer 30. A substrate 50 may be provided on thesecond electrode layer 40. The first spacer 33 may support the firstelectrode layer 30 such that the first electrode layer 30 may not be incontact with the light guide plate 20 and may appear to be suspendedabove the light guide plate 20. A gap G may be formed between the lightguide plate 20 and the first electrode layer 30.

The first electrode layer 30 may include one or more first holes 31. Thesecond electrode layer 40 may include one or more second holes 42. Thefirst and second holes 31 and 42 may not face with each other. Forexample, as shown in FIG. 2, the first and second holes 31 and 42 may bearranged in zigzag in a horizontal direction such that the first andsecond holes 31 and 42 may not overlap each other. As the micro-opticalswitches MOS are turned on or off, the second holes 42 may be closed oropened. When no voltage is applied between the first and secondelectrode layers 30 and 40, the micro-optical switches MOS may be turnedoff, and in this case, light may pass through the first and second holes31 and 42. When a voltage is applied between the first and secondelectrode layers 30 and 40, the micro-optical switches MOS may be turnedon, and in this case, the second holes 42 may be closed to block light.

The shapes, sizes, and numbers of the first and second holes 31 and 42may be variously selected as long as the first and second holes 31 and42 do not overlap each other when the micro-optical switches MOS areturned on. For example, the first and second holes 31 and 42 may havevarious shapes such as quadrangular, circular, or diamond-like shapes.FIG. 3 illustrates an example in which the first and second holes 31 and42 have a rectangular shape. For example, the first holes 31 may bearranged in a 2×2 form, and the second holes 42 may be arranged in a 3×2form.

When the micro-optical switches MOS are turned on, the second holes 42may be closed by the first electrode layer 30. For example, a width W1between the first holes 31 of the first electrode layer 30 may begreater than the width W2 of the second holes 42.

For example, the first and second electrode layers 30 and 40 may beformed of an opaque conductive material. The opaque conductive materialmay include a light blocking material. For example, the first and secondelectrode layers 30 and 40 may include an opaque conductive material.The first and second electrode layers 30 and 40 may include at least onemetal selected from titanium (Ti), gold (Au), silver (Ag), platinum(Pt), copper (Cu), aluminum (Al), nickel (Ni), and chromium (Cr).However, the first and second electrode layers 30 and 40 are not limitedthereto.

An insulation layer 45 may be further provided on the second electrodelayer 40. The insulation layer 45 may prevent a short circuit betweenthe first and second electrode layers 30 and 40. In addition, reflectivelayers may be formed on surfaces of the first and second electrodelayers 30 and 40. For example, a reflective layer may be providedbetween the first and second electrode layers 30 and 40 to increasereflectivity of light which is incident from the outside.

The first and second electrode layers 30 and 40 may be separate (e.g.,spaced apart) from each other. A second spacer 43 may be providedbetween the first and second electrode layers 30 and 40 to support thesecond electrode layer 40. The second spacer 43 may maintain a gapbetween the first and second electrode layers 30 and 40. In addition,the second spacer 43 may support the first electrode layer 30 when thefirst electrode layer 30 moves toward the second electrode layer 40. Thesecond spacer 43 may have a thickness suitable for smooth on-offswitching of the micro-optical switches MOS. For example, if the firstand second electrode layers 30 and 40 are too close, the first andsecond electrode layers 30 and 40 may come into contact with each othereven though a voltage is not applied between the first and secondelectrode layers 30 and 40, and thus the micro-optical switches MOS mayabnormally operate. Therefore, the first and second electrode layers 30and 40 may be spaced apart from each other by a suitable distance. Atleast two second spacers 43 may be provided. For example, post-shapedsecond spacers 43 may be disposed at four corners between the first andsecond electrode layers 30 and 40. However, the exemplary embodimentsare not limited thereto. For example, two second spacers 43 shaped likea sidewall may be disposed between the first and second electrode layers30 and 40. For example, the second spacer 43 may include an elasticmaterial. For example, the second spacer 43 may be formed of an elasticmaterial. For example, the second spacer 43 may be formed of an elasticpolymer. However, the second spacer 43 is not limited thereto. Forexample, the second spacer 43 may include a material such as silicone,polysiloxanes, polyurethanes, polysilicone-polyurethane, rubber,ethylene-vinyl acetate copolymers, phenolic nitrile rubber, styrenebutadiene rubber, polyether-block-amides, polyolefins, or gels.

The substrate 50 provided on the second electrode layer 40 may be atransparent substrate. For example, the substrate 50 may be a glass orplastic substrate. The substrate 50 may be disposed on a side of thesecond electrode layer 40 through which light passing through the secondholes 42 is output.

The first electrode layer 30 may have a very small thickness, forexample, in the range of several nanometers to several tens ofnanometers. The first electrode layer 30 having a very small thicknessmay be supported as if floating in air, and as the micro-opticalswitches MOS are turned on and off, the first electrode layer 30 may bemoved. However, since the second electrode layer 40 is provided on thesubstrate 50, the second electrode layer 40 may have a higher degree offlatness than the first electrode layer 30 supported in air. Flatnessmay affect reflectivity. That is, a layer having a relatively highdegree of flatness may have a relatively high reflectivity compared to alayer formed of the same material and having a relatively low degree offlatness. For example, the second electrode layer 40 may have areflectivity of about 70% or greater. For example, the second electrodelayer 40 may have a reflectivity of about 90% or greater. The secondelectrode layer 40 may have a higher degree of reflectivity with respectto external light than the first electrode layer 30. The secondelectrode layer 40 provided on the substrate 50 may be disposed on anouter side of the mirror display such that the second electrode layer 40may function as a mirror. Here, the outer side may refer to anexit-surface side of the mirror display through which light forming animage is output.

As described above, the micro-optical switches MOS may be arranged onthe light guide plate 20 in an array structure. The micro-opticalswitches MOS may be independently turned of and off by an electricalmethod. In addition, the micro-optical switches MOS may be independentlymoved by a mechanical method. That is, the micro-optical switches MOSmay individually apply a voltage between the first and second electrodelayers 30 and 40. To this end, the micro-optical switches MOS mayinclude a driving circuit unit 60 for applying a voltage between thefirst and second electrode layers 30 and 40. The driving circuit unit 60may include a passive matrix structure or an active matrix structure.For example, if the driving circuit unit 60 includes an active matrixstructure, the micro-optical switches MOS may be turned on and off bywell-known thin-film transistors. For example, the first electrode layer30 may include pixel electrodes configured to individually apply avoltage to the pixels PX, and the second electrode layer 40 may includea common electrode. Alternatively, the first electrode layer 30 mayinclude a common electrode, and the second electrode layer 40 mayinclude pixel electrodes.

With reference to FIGS. 2 and 4, an operation of the mirror display willnow be described.

FIG. 2 illustrates a turned-off state of the micro-optical switch MOS.When no voltage is applied between the first and second electrode layers30 and 40, the first and second electrode layers 30 and 40 stay in aseparate state, and the first and second holes 31 and 42 stay in anopened state. At this time, light emitted from the light source 10 maypropagate through the light guide plate 20 and may then exit through thefirst and second holes 31 and 42. Light L1 emitted from the light source10 may be incident on the light guide plate 20, and a portion of thelight L1 may be repeatedly reflected by upper and lower surfaces of thelight guide plate 20 toward a side distant from the light source 10.Another portion of the light L1 may be reflected in the light guideplate 20 and may propagate toward the second electrode layer 40 throughthe first holes 31. Light incident on the second electrode layer 40 maybe reflected back to the first electrode layer 30 and may be reflectedagain by the first electrode layer 30 such that the light may exit themirror display through the second holes 42 and the substrate 50. Sincethe first and second electrode layers 30 and 40 include a reflectivematerial, optical switching may be possible using the first and secondelectrode layers 30 and 40.

FIG. 4 illustrates a turned-on state of the micro-optical switch MOS.When a voltage is applied between the first and second electrode layers30 and 40, the first electrode layer 30 may be pulled toward the secondelectrode layer 40 by an electrostatic attractive force. Since thesecond electrode layer 40 is fixed to the substrate 50 and the firstelectrode layer 30 is separate from the light guide plate 20, the firstelectrode layer 30 may be moved toward the second electrode layer 40.Thus, if the first electrode layer 30 is brought into contact with thesecond electrode layer 40, the second holes 42 may be closed by thefirst electrode layer 30. Then, since the second holes 42 are closed andthe second electrode layer 40 includes an opaque reflective material,light may not be output through the second holes 42.

FIG. 5 illustrates a method of forming images by individually turning onor off the micro-optical switches MOS of the micro-optical switch arraySA according to the pixel PX of the mirror display. The mirror displaymay further include an image signal input unit 70 configured to controlthe amount of light transmission by adjusting the time period duringwhich a voltage is applied between the first and second electrode layers30 and 40. In other words, the image signal input unit 70 may expressthe gray scale of images by individually adjusting time periods duringwhich a voltage is applied to the micro-optical switches MOS. Inaddition, while the first to third light sources 11 to 13 configured toemit light having different wavelengths are operated in a time sequence,turning on and off of the micro-optical switches MOS may be controlledto display color images.

As described above, according to an exemplary embodiment, the mirrordisplay may display color images without using a color filter.

In the above description, an image display operation of the mirrordisplay is described. However, the mirror display may be used as amirror as well as an image display. Referring to FIG. 2, light LOincident on the mirror display from the outside (hereinafter, alsoreferred to as external light LO) may arrive at the second electrodelayer 40 through the substrate 50. Since the second electrode layer 40includes an opaque reflective material, the external light LO incidenton the second electrode layer 40 may be reflected by the secondelectrode layer 40 to the outside. Therefore, when the micro-opticalswitches MOS are turned off, the mirror display may be used as a mirrorowing to the second electrode layer 40. In addition, as shown in FIG. 4,when the micro-optical switches MOS are turned on, if external light LOis incident on the mirror display, the external light LO may bereflected by the first and second electrode layers 30 and 40 to theoutside. Therefore, when the micro-optical switches MOS are turned on,the mirror display may be used as a mirror owing to the first and secondelectrode layers 30 and 40. The second electrode layer 40 may have ahigher degree of reflectivity than the first electrode layer 30.Therefore, the second electrode layer 40 may function as a main mirror.That is, owing to the second electrode layer 40, the mirror display mayfunction as a mirror independent of turning on or off of themicro-optical switches MOS.

As described above, the mirror display of an exemplary embodiment mayfunction as an image display according to turning on and off of themicro-optical switches MOS. In addition, the mirror display may functionas a mirror. When all the micro-optical switches MOS of the mirrordisplay are turned on, the mirror display does not output light, andthus the mirror display may only function as a mirror.

Since the second electrode layer 40 reflecting external light LO isfixed to the substrate 50 when the micro-optical switches MOS are turnedon and off, the second electrode layer 40 may maintain its reflectivity.Therefore, the mirror display of the exemplary embodiment may stablyfunction as a mirror. In addition, although the second electrode layer40 has a very thin thickness, since the second electrode layer 40 isstably attached to the substrate 50, the reflectivity of the secondelectrode layer 40 may be high. Therefore, the second electrode layer 40may improve the mirror function of the mirror display without loweringthe light transmission efficiency of the mirror display. For example,the second electrode layer 40 may have a reflectivity of about 70% orgreater. For example, the second electrode layer 40 may have areflectivity of about 90% or greater. In an exemplary embodiment, sincelight transmission is controlled using the micro-optical switches MOSwithout using liquid crystals, optical efficiency may be increased.Layers or structures such as a color filter or a translucent film may benecessary for displaying images using a liquid crystal layer. However,the mirror display of an exemplary embodiment does not use a colorfilter for displaying images and additional layers for functioning as amirror. Therefore, the optical efficiency of the mirror display may behigher than that of liquid crystal displays.

FIG. 6 illustrates an exemplary case in which the mirror displayillustrated in FIG. 2 further includes a light reflecting layer 25 andan optical film 47. The light reflecting layer 25 may be disposed on alower portion of the light guide plate 20. The light reflecting layer 25reflects light that may leak through the lower portion of the lightguide plate 20, and thus the light reflecting layer 25 may improve theoptical efficiency of the mirror display.

For example, the optical film 47 may be disposed at positionscorresponding to the second holes 42 to cover the second holes 42. Theoptical film 47 is transparent and capable of refracting light in anupward direction. For example, the optical film 47 may include adiffusing plate or a polarizing plate.

FIG. 7 illustrates an exemplary case in which the mirror displayillustrated in FIG. 2 further includes a light diffusing layer 16, afirst anti-adhesion layer 36, and a second anti-adhesion layer 37.

The light diffusing layer 16 may be disposed on an exit surface of thelight guide plate 20. The light diffusing layer 16 may diffuse lightexiting from the light guide plate 20 such that the light may propagatein an upward direction. For example, the first anti-adhesion layer 36may be provided between the light guide plate 20 and the first electrodelayer 30. As shown in FIG. 7, the first anti-adhesion layer 36 may beprovided between the light diffusing layer 16 and the first electrodelayer 30. A very small gap G may be formed between the light guide plate20 and the first electrode layer 30 or between the light diffusing layer16 and the first electrode layer 30. Therefore, when the first electrodelayer 30 is moved, the first electrode layer 30 may adhere to the lightguide plate 20 or the light diffusing layer 16, and thus switchingerrors may occur. The first anti-adhesion layer 36 may reduce suchswitching errors.

The second anti-adhesion layer 37 may be provided on the secondelectrode layer 40 or the insulation layer 45. However, the secondanti-adhesion layer 37 is not limited thereto. For example, the secondanti-adhesion layer 37 may be provided on the first electrode layer 30.When the first electrode layer 30 is moved and brought into contact withthe second electrode layer 40, the second anti-adhesion layer 37 mayprevent the first electrode layer 30 from adhering to the secondelectrode layer 40. The second anti-adhesion layer 37 may be provided insome small regions of the second electrode layer 40.

FIG. 8 illustrates an exemplary usage of the mirror display according toan exemplary embodiment. For example, the mirror display may be used asa substitute for a mirror in a bathroom. In a bathroom, the mirrordisplay may function as a mirror and may provide a variety ofinformation by displaying images. For example, the mirror display maydisplay information such as date, weather, or temperature. In anotherexample, the mirror display may be provided in a powder room, and imagesof clothes may be displayed on the mirror display so that users may lookat themselves in the mirror display when dressing themselves. That is,the mirror display may be used as an augmented reality display.Furthermore, the mirror display may display information about a user'shealth. That is, the mirror display may be used as a healthcare display.Also, the mirror display may be used for various other purposes as well.

As described above in the exemplary embodiments, the mirror display hasa simple structure, and thus the mirror display may easily bemanufactured, for example, through semiconductor processes having highproductivity. In addition, when the micro-optical switches MOS areturned on, the second holes 42 may be closed to prevent light leakageand improve the contrast of the mirror display. In addition, since themicro-optical switches MOS are turn on and off by the effect ofelectrostatic attractive force, the micro-optical switches MOS have alow operating voltage and a high operating speed. In addition, sincetotal internal reflection is not required for the light guide plate 20,the light guide plate 20 may be manufactured with relatively low costs.

In addition, since the first and second electrode layers 30 and 40 foroperating the micro-optical switches MOS are also used as mirrors, themirror display does not need additional components for reflectingexternal light, and thus manufacturing costs of the mirror display maybe reduced. Furthermore, according to the exemplary embodiments, theimage display mode and mirror image display mode of the mirror displaydo not have a trade-off relationship, and thus the mirror display mayhave a high degree of optical efficiency in each of the modes.

Next, a method of manufacturing a mirror display according to anexemplary embodiment will be described. Referring to FIG. 9, a firstelectrode layer 110 may be disposed on a substrate 100. The substrate100 may include a transparent material, and thus light may betransmitted through the substrate 100. For example, the substrate 100may include glass. The first electrode layer 110 may include aconductive material having a light blocking ability. The first electrodelayer 110 may include a light reflecting material. The first electrodelayer 110 may include at least one of titanium (Ti), gold (Au), silver(Ag), platinum (Pt), copper (Cu), aluminum (Al), nickel (Ni), andchromium (Cr). However, the first electrode layer 110 is not limitedthereto.

Referring to FIG. 10, the first electrode layer 110 may be patterned toform one or more first holes 111. Referring to FIG. 11, an insulativematerial layer 112 may be formed on the first electrode layer 110including the first holes 111. Referring to FIG. 12, the insulativematerial layer 112 may be etched to form an insulation layer 113corresponding to the first electrode layer 110. For example, theinsulation layer 113 may include a light blocking material.

Referring to FIG. 13, a first layer 115 may be disposed on theinsulation layer 113 and the substrate 100. The first layer 115 may be asacrifice layer. Referring to FIG. 14, the first layer 115 may be etchedto form holes 117. Referring to FIG. 15, a spacer material may beapplied to fill the holes 117 and thus to form a first spacer 118. Next,a second electrode layer 120 may be disposed on the first layer 115.Since the second electrode layer 120 is disposed on the first layer 115being a sacrifice layer, the flatness of the second electrode layer 120may be low. Therefore, there may be a limit to increasing thereflectivity of the second electrode layer 120. However, since the firstelectrode layer 110 is disposed on the substrate 100, the firstelectrode layer 110 may have a higher degree of flatness than the secondelectrode layer 120. That is, the first electrode layer 110 may have arelatively high degree of reflectivity. For example, the first electrodelayer 110 may have a reflectivity of about 70% or greater. For example,the first electrode layer 110 may have a reflectivity of about 90% orgreater.

Also, instead of forming the first spacer 118 through a separate processas described above, the first spacer 118 may be formed together with thesecond electrode layer 120 by depositing the second electrode layer 120on the structure shown in FIG. 14.

Referring to FIG. 16, the second electrode layer 120 may be etched toform second holes 122. Referring to FIG. 17, the first layer 115 may beremoved using the second holes 122. For example, the first layer 115 maybe removed through an ashing process.

Referring to FIG. 18, before the first layer 115 is removed, a spacermaterial layer may be disposed on the structure shown in FIG. 16, andthe spacer material layer may be etched to form a second spacer 130.

Referring to FIG. 19, the structure shown in FIG. 18 may be coupled to alight guide plate 140. When the structure shown in FIG. 18 is coupled tothe light guide plate 140, the second electrode layer 120 may face thelight guide plate 140. Then, the second electrode layer 120 and thelight guide plate 140 may be coupled together with a predetermined gapbeing formed therebetween by the second spacer 130. In the above, thesecond spacer 130 is formed on the second electrode layer 120. Inanother example, however, the second spacer 130 may be formed on thelight guide plate 140.

As described above, according to one or more of the above exemplaryembodiments, the mirror display may be simply manufactured throughsemiconductor processes. The mirror display may be manufactured throughmicro-optical switch forming processes without having to perform anadditional mirror forming process, and accordingly, the mirror displaymay be manufactured with low costs and high productivity.

As described above, according to one or more of the above exemplaryembodiments, the optical reflectivity of the mirror display is increasedusing the micro-optical switches MOS, and thus the mirror display mayfunction as a mirror without additional components. According to one ormore of the above exemplary embodiments, the mirror display may displayimages using the micro-optical switches MOS without lowering the lighttransmission efficiency of the mirror display.

It should be understood that exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exemplaryembodiment should typically be considered as available for other similarfeatures or aspects in other exemplary embodiments.

While one or more exemplary embodiments have been described withreference to the figures, it will be understood by those of ordinaryskill in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the exemplaryembodiments as defined by the following claims.

What is claimed is:
 1. A mirror display comprising: a light source; alight guide plate configured to guide light emitted from the lightsource; a first electrode layer spaced apart from the light guide plateand comprising at least one first hole; a first spacer provided betweenthe light guide plate and the first electrode layer; a second electrodelayer spaced apart from the first electrode layer and comprising atleast one second hole not facing the first hole; and a substrateprovided on the second electrode layer.
 2. The mirror display of claim1, wherein in response to applying a voltage between the first electrodelayer and the second electrode layer, the first electrode layer is movedtoward the second electrode layer.
 3. The mirror display of claim 2,wherein in response to applying a voltage between the first electrodelayer and the second electrode layer, the second electrode layer is notmoved.
 4. The mirror display of claim 1, wherein in response to applyinga voltage between the first electrode layer and the second electrodelayer, the first electrode layer closes the second hole.
 5. The mirrordisplay of claim 1, wherein the substrate comprises a transparentmaterial.
 6. The mirror display of claim 5, wherein the substratecomprises a glass substrate.
 7. The mirror display of claim 1, furthercomprising an insulation layer provided on the second electrode layer.8. The mirror display of claim 1, further comprising an optical filmcovering the at least one second hole.
 9. The mirror display of claim 8,wherein the optical film comprises a diffusing plate or a polarizingplate to guide light in an upward direction.
 10. The mirror display ofclaim 1, wherein the light source comprises a plurality of light sourcesconfigured to emit light having different wavelengths.
 11. The mirrordisplay of claim 10, wherein the plurality of light sources are turnedon and off in a time sequence so as to display color images.
 12. Themirror display of claim 1, further comprising an image signal inputterconfigured to control light transmission by varying a time period duringwhich a voltage is applied between the first electrode layer and thesecond electrode layer.
 13. The mirror display of claim 1, wherein thesubstrate is provided on a side of the second electrode layer throughwhich light passing through the second hole is output.
 14. The mirrordisplay of claim 1, wherein the second electrode layer has areflectivity of 70% or greater.
 15. The mirror display of claim 1,wherein the second electrode layer reflects external light incident onthe mirror display.
 16. The mirror display of claim 1, furthercomprising a gap formed between the light guide plate and the firstelectrode layer.
 17. The mirror display of claim 1, further comprising asecond spacer provided between the first electrode layer and the secondelectrode layer.
 18. The mirror display of claim 1, wherein the firstelectrode layer comprises pixel electrodes, and the second electrodelayer comprises a common electrode.
 19. A method of manufacturing amirror display, the method comprising: preparing a light guide plate;providing a first electrode layer on a substrate; etching the firstelectrode layer to form at least one first hole in the first electrodelayer; providing a second electrode layer spaced apart from the firstelectrode layer; etching the second electrode layer to form at least onesecond hole in the second electrode layer; providing the secondelectrode layer to face the light guide plate; and coupling the secondelectrode layer to the light guide plate using a first spacer.
 20. Themethod of claim 19, further comprising: providing a first layer on thefirst electrode layer; etching the first layer to form a hole; forming asecond spacer by filling the hole with a spacer material; providing thesecond electrode layer on the first layer; and removing the first layer.21. The method of claim 19, wherein the etching the second electrodelayer comprises etching the second electrode layer such that the secondhole does not face the first hole.
 22. The method of claim 19, whereinthe first electrode layer has a reflectivity of 70% or greater